It’s a mystery that spans decades, continents and cultures, and bridges one Toronto woman’s life with her childhood in Japan: what happened to Fukue?

In 1988, Jessica Stuart was nine years old. Her family embarked on a cultural odyssey that would greatly influence her life: the Stuarts dug up their middle-class roots in Vancouver’s Jewish community and replanted them in a rural Japanese town called Saku for a year.

It was during this absorbing year that Jessica met Fukue, a bright and bubbly girl with rosy red cheeks and an endless smile. Fukue and Jessica became like sisters, spending their days frolicking in the autumn leaves, dancing under snow-blanket...